package cn.tedu.sp06.fb;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;

@Component
public class ItemFB implements FallbackProvider {
    /**
     * 设置调用哪个后台服务,会应用当前降级类
     *"item-service"只针对商品降级
     * "*"对所有服务都降级
     * null对所有服务都降级
     * */
    @Override
    public String getRoute() {
        return "item-service";
    }
    //发回给客户端响应的数据
    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();
            }

            @Override
            public void close() {
            //用来关闭下面方法的流
            //BAIS 流内存数组的流,不占用底层系统资源,不需要关闭
            }

            @Override
            public InputStream getBody() throws IOException {
                //JsonResult - {code:500,msg:调用商品失败,data:null}
                String json = JsonResult.err().code(500).msg("调用商品失败").toString();
                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders h = new HttpHeaders();
                h.add("Content-Type","application/json;charset=UTF-8");
                return  h;
            }
        };
    }
}
